Detection: Splunk Stored XSS via Data Model objectName Field

Updated Date: 2024-10-17 ID: 062bff76-5f9c-496e-a386-cb1adcf69871 Author: Rod Soto Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies attempts to exploit a stored cross-site scripting (XSS) vulnerability in Splunk Enterprise via the Data Model object name field. It detects this activity by analyzing web access logs (splunkd_webx) for specific URI patterns and non-null query parameters. This activity is significant because it allows authenticated users to inject and store malicious scripts, leading to persistent XSS attacks. If confirmed malicious, this could enable attackers to execute arbitrary scripts in the context of other users, potentially leading to data theft, session hijacking, or further compromise of the Splunk environment.

Search

1`splunkd_webx` uri=/*/splunkd/__raw/servicesNS/*/launcher/datamodel/model* uri_query!=null 
2| stats count by _time host status clientip user uri 
3| `splunk_stored_xss_via_data_model_objectname_field_filter`

Data Source

Name	Platform	Sourcetype	Source
Splunk	Splunk	`'splunkd_ui_access'`	`'splunkd_ui_access.log'`

Macros Used

Name	Value
splunkd_webx	`index=_internal sourcetype=splunk_web_access`
splunk_stored_xss_via_data_model_objectname_field_filter	`search *`

splunk_stored_xss_via_data_model_objectname_field_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1189	Drive-by Compromise	Initial Access

KillChainPhase.DELIVERY

NistCategory.DE_AE

Cis18Value.CIS_10

APT19

APT28

APT32

APT37

APT38

Andariel

Axiom

BRONZE BUTLER

CURIUM

Daggerfly

Dark Caracal

Darkhotel

Dragonfly

Earth Lusca

Elderwood

Lazarus Group

Leafminer

Leviathan

Machete

Magic Hound

Mustard Tempest

PLATINUM

PROMETHIUM

Patchwork

RTM

Threat Group-3390

Transparent Tribe

Turla

Windigo

Windshift

Winter Vivern

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	False

This configuration file applies to all detections of type hunting.

Implementation

This vulnerability only affects Splunk Web enabled instances. This detection does not require you to ingest any new data. The detection does require the ability to search the _internal index.

Known False Positives

This search may produce false positives and does not cover exploitation attempts via code obfuscation, focus of search is suspicious requests against "/en-US/splunkd/__raw/servicesNS/*/launcher/datamodel/model" which is the injection point.

Associated Analytic Story

Splunk Vulnerabilities

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A potential XSS attempt has been detected from $user$	25	50	50

The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`/opt/splunk/var/log/splunk/web_access.log`	`splunk_web_access`
Integration	✅ Passing	Dataset	`/opt/splunk/var/log/splunk/web_access.log`	`splunk_web_access`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 4